Espar hydronic heating system

[matts997]

I got the furance up and running after topping it off with coolant. Not sure exactlly why....I can only conclude that there was a small coolant leak from the hoses leading to & from the main Espar unit and that tightening up the hose clamps stopped the leak. As I sit here on the boat, it’s now been running (and cycling off/on) for ~ 2 hrs with no sign of a leak.

I also hired a Yanmar and HVAC tech I know to come out for an hour and check everything. He explained what each of the valves do (the 2 lower valves are 3-way and the upper, middle valve is a 2-way, my guess was incorrect). And how the different combinations of valve settings affect how the fresh water is heated; there’s also an option for having the engine heat the cabin and fans running when motoring, with the Espar furance turned off.

Thanks for these manuals Bob--the figures/schematics are helpful as a model for mapping out my own system. Appreciate all the help I got from this thread!

Matt

 

[paulheth]

Matts997 congratulations on your success in getting things going. You have attracted a group of knowledgeable and helpful posters. This thread has been very educational to me on my voyage down the Hydronic Heating trail. I am in a similar situation, the 'new to me' boat has one of these D5s and similar hose setup. It now fires up (after refilling and checking for leaks) and successfully heats the boat. However I do have one leak that is more of a problem and it's coming from what looks to be some kind of 'mixing device' that I need some help identifying. I've attached my version of crude system diagrams and pictures and would love if anyone can help me name the part so I can begin to research a repair/replacement.

I should mention my system is a bit more simplistic design as it only has 1 valve (that I can find after considerable search) which appears to isolate the front half of the boat for seasonal heating. It does appear that both my engine and electric hot water heater are pipe inline with no valves to isolate the heating source. Any comments welcome.

Thanks.

 

[matts997]

Wish I could help, but I don’t know what that is....seems unlikely it’s a heat exchanger being where it is, coming out of the hot water heater?? Hopefully dkinzer or someone else on this thread picks this up, or someone else w/ a Catalina 320. Good luck!

 

[paulheth]

Wish I could help, but I don’t know what that is....seems unlikely it’s a heat exchanger being where it is, coming out of the hot water heater?? Hopefully dkinzer or someone else on this thread picks this up, or someone else w/ a Catalina 320. Good luck!

Thanks for the comment. I should update my profile - while I still have the 320, this is actually on a 2008 Beneteau 40 that is new to me. There is a heat exchanger in the loop but this seems to a way to interface the hot water heating circuit with the hot water heater and even seems to somehow 'overlap' with the how tap water circuit? At closer inspection it almost looks like there is some kind of air 'bleading' hole? The leak is at the seam between what looks like the two pipes. Some kind of o-ring inside? Maybe a one off custom?

My next step is to drain the system and take this thing out and see if it comes apart. Still sure exactly what I will learn by doing that though.

 

[east coaster]

Although I have a espar D4 air unit that I installed on my 2002 310, my response has to do with the fuel and fouling of the combustion chamber. I run my unit at full blast for at least 30 minutes a month summer or winter. This prevents or at least reduces the carbon build up in the unit which if bad enough will shut it down. I have had to take it apart and clean the carbon out, a loathsome, dirty job at best. After discussing this with the dealer he recommended that I use a separate fuel tank for the unit and he subsequently sent me a 7 litre tank that I plumbed into the unit, eliminating the connection from my main diesel tank. He also advised that I mix the diesel fuel 50/50 with kerosene. It has provided a cleaner burn and prevents the diesel from gelling, despite adding antigel to the main tank. On the East Coast, temperatures are not as benign, relatively speaking, as they are in the PNW. In addition, I carry a small fuel tank premixed with this 50/50 mix if we have to run the D4 for an extended period. This may not help with the hydronic problem, however I wanted to share my experience regarding the espar combustion chamber fouling and it's prevention for other espar or similar units. Thanks for your patience.

 

[matts997]

My Espar draws its fuel from the engine’s fuel tank, but a separate fuel tank is definitely the way to go. How long can you run the furnace on a 7 L tank?

The other problem avoided by having a separate tank is fuel additives for the engine running through the furnace. Every winter I add a combination of Biobor JF and Starr Tron diesel enzyme treatments, but I always worry that this might foul the furnace, although I've had no problems with it yet.

 

[east coaster]

On a full tank I usually get 8-10 hours, but much of that is dependent on temperatures in and out of the boat, what hatches are open, how many times crew or the admiral go below and whether I have the cockpit enclosure on and what temp the espar is set for. Probably a few other factors that have forgotten as well. As for additives in the espar fuel tank, I have spoken at length with them and they have assured me that using a 50/50 blend of diesel and kerosene eliminates the need for additives. However I, like you add bio bor, seafoam and injector cleaner in the correct portions for a 7 litre tank. Not had any issues with using the additives. The other factor is if the espar has been running at a low speed, then prior to shutting it down, espar advises to increase the temp to max and run for 10/15 minutes to burn off any carbon in the combustion chamber. A fellow boater just finished cleaning the combustion chamber on his unit. He said it was a " loathsome messy terribly job" that he did not wish on anyone. He now runs on kerosene only. Again this is my experience with using the espar.

 

[Hello Below]

After discussing this with the dealer he recommended that I use a separate fuel tank for the unit and he subsequently sent me a 7 litre tank that I plumbed into the unit, eliminating the connection from my main diesel tank.

At your convenience, could you take a photo of your auxiliary 7L diesel tank and post it along with the manufacturer. It seems Moeller does not sell in that size other than portable. I do see a few interesting ones in both stainless and plastic material listed on Amazon that could be permanently mounted. Come to think of it, a permanent one may be difficult to refill.

 

[dlochner]

At your convenience, could you take a photo of your auxiliary 7L diesel tank and post it along with the manufacturer. It seems Moeller does not sell in that size other than portable. I do see a few interesting ones in both stainless and plastic material listed on Amazon that could be permanently mounted. Come to think of it, a permanent one may be difficult to refill.

Here's source for tanks and the fittings.

Fuel Tanks Fuel Pick-up tubes and Accessories

www.suremarineservice.com

 

[Hello Below]

Here's source for tanks and the fittings.

Fuel Tanks Fuel Pick-up tubes and Accessories

www.suremarineservice.com

Complete with fuel deck fill. Thank you.

 

[Hayden Watson]

I have an Espar S3 D5E heater and it is plumbed into the main engine fuel tank. Over the past three years, I have never noticed it to use enough fuel to worry about having its own fuel tank. It only burns 0.59_l/hr [0.15_g/hr] on high which is only for the first few minutes after it fires up. After that, it is typically on its minimum burn rate of 0.15_l/hr [ 0.04_g/hr] when it is actually heating. Much of the time it is actually not burning any fuel and just using the heat that is in the water of the system.